The normally picturesque canals in Bruges have been hidden under a thick layer of Duckweed for several days, which authorities confirm is not dangerous
It’s not St Patrick’s Day, but still the canals of Bruges have decided to turn bright green. The culprit is Duckweed (Lemna), an aquatic plant that often grows – rapidly and aplenty – in still water.
“The duckweed developed in the Kapucijen canal, a zone with relatively still-standing water,” explains Bruges mayor Dirk De fauw (CD&V). “Due to certain circumstances, the water system has not been flushed from the inner wall for a while, and that has promoted the growth of duckweed.”
At these temperatures, duckweed easily doubles in surface area every day
Bruges mayor Dirk De fauw
While it may or may not be attractive to passersby, the floating green carpet does not pose any risk to human or animal health: There’s enough oxygen in the water for fish, and the famous swans and other fowl actually eat it.
“We are resuming the flushing of the canals, so we expect that they will be completely free of duckweed in about a week.”
The mild weather of the past few weeks may have also played a role in the sudden growth of the duckweed. “This phenomenon does not occur in colder weather,” the mayor confirms. “And it has happened very quickly now due to the mild weather. At these temperatures, duckweed easily doubles in surface area every day.”